Scaffold attachment factor B1 (SAFB1) is a chromatin associated protein that interacts with DNA elements termed S/MARs (scaffold or matrix attachment regions) but is not part of the nuclear matrix. SAFB1 is ubiquitously expressed and appears to be a multifunctional protein involved in chromatin organization, mRNA processing and transcriptional regulation. SAFB1 has been demonstrated to interact with and function as a corepressor with many nuclear receptors such as estrogen receptor-alpha, PPAR-gamma, and FXR-alpha.